Rotary pump



- Get. 8, 1-940. F, E BRADY 2,217,211

ROTARY PUMP Filed Sept. 11, 195? 3 Sheets-Shee l s i x INVENTOR W Z &

-/ )Zzn ATTORN EY @ct 89 1940- F. E. BRADY 2,217,213

ROTARY FUMF Filed Sept. ll, 193,7 3 Sheets-Sheet 2 INVENTOR ATTORNEY F.E. BRADY ROTARY FUMP 'Fiied Sept. 11, 19s";

3 Sheets-Sheet 3 INVENTOR W BY I V ATTORN EY Patented Oct. 8, 1940PATENT OFFICE ROTARY PUMP Francis E. Brady, Connersville, Ind., assignorto Roots-Connersville Blower Corporation, Connersvllle, Ind., acorporation of Indiana Application September 11, 1937, Serial No.163,469

6 Claims.

This invention relates to pumps and more particularly to self-primingliquid pumps. One object of the invention is the provision of aself-priming pump which is eflicient and capai ble of operating againstcomparatively high pressure heads and of creating a high degree ofsuction and of gas scavenging action, embodying a rotatable memberhaving an annular series of blades which operate in a raceway of anenclosingcasing in which is a pocket, Just past the outlet port, inwhich sufilcient pressure is created to drive gas or vapor from the baseportions of the impeller buckets or chambers, the gas being withdrawnthrough a conducting passage which communicates with the inner portionsof the impeller chambers.

Other objects and advantages of the invention will be apparent from thefollowing description, the appended claims and the accompanying :odrawings, in which Fig. 1 is a front elevation of a pump embodying thepresent invention, a portion of the pump being-broken away and shown insection;

Fig. 2 is a section on the line 2-2 of Fig. 1;

25 Fig. 3 is a section-on the line 3--3 of Fig. 1;

Fig. 4 is a fragmentary view of a portion of the impeller looking in thedirection of the arrow 3 of Fig. 3; and

Fig. 5 is a central vertical section through a s0 somewhat modified formof construction.

Referring more particularly to the drawings by reference numerals, Itgenerally designates the casing and H the rotatable impeller of a'self-priming pump adapted to handle gasoline is and other liquids andcapable of creating a con-' siderable suction and of delivering theliquid handled under considerable pressure and in an efficient manner.

The casing is preferably constructed in two 40 main sections l2 and i3connected together by bolts It to provide anannular raceway I5 in whichthe impeller blades operate. The blades l6 of the impeller H, as shown,are constructed generally in accordance with .my prior Patent 45 No.2,042,499, granted June 2, 1936, and, as indicated in Fig. 1, theseblades are inclined forwardly in the direction of rotation at an angleof the order of about 25 to a radial line through the axis of rotation.With such a forward inclina- 50 tion of the blades there is a highdegree of efiectiveness of the outer parts of the blades on the liquidas the blades operate in the annular raceway 15, giving an effectivepumping action from the inlet passage l8 to the outlet port 20 which is55 arranged for the peripheral discharge of the liqshown in Fig. 3.

uld through the outlet passage 2|. The inlet port I8 is herein shown asa peripheral inlet delivering the liquid at a comparatively high pointnear the top of the impeller and into the annular raceway. The bladesmay be V-shaped as viewed from the ends of the blades, and as shown inFig. 4, so that opposite sides of the blades are inclined forwardly andoutwardly at an angle of the order of 130 to one another. With thissubstantially V-shaped ,arrangement of blades a high degree of pumpingefiiciencyis obtained.

As will be noted from Fig. 1, the radial extent of the blades is lessthan 10% of the diameter of the impeller, and the spacing :betweenadjacent blades is not in excess of 10% of the diameter of the impeller.The blades are thus comparatively small as compared to the diameter ofthe blade supporting portion of the impeller so that there are a largenumber of rather small buckets or chambers provided between the bladesof the impeller. These chambers are exposed at their peripheral outerportions and also at their lateral portions to the liquid in the racewayl5 as As will be apparent from Fig. 3, the body-portion of the impellerH is secured, as by means of screw threads, to the rotatable shaft 24which operates in bearings 25 in the casing. The shaft is driven in anysuitable manner so as to operate counter-clockwise as viewed in Fig. 1.ing against leakage of the material Ipumped alongthe shaft and past thebearings 25, the bearing member 25 at the left of the pump in Fig. 3 hasa bearing surface 26 engaged by the end of the metallic sealing member2's, these two portions having engaging smooth sealingsurfaces. Thesealing member 2'! rotates with the shaft 24, having a drivingconnection therewith through the spring 28 which engages at one end witha notch in the member 2'1 and at the other end with a notch in theimpeller body. The spring 28 also bears yieldingly against a pressuredisk 29 which maintains suitable packing material 30 undersuflicientcompression to prevent passage of liquid along the shaft inside of themember 21. A similar construction is provided at the other side of theimpeller.

At..the top of the casing is a reservoir member 32 receiving the liquidpumped from the outlet passage 2|, and having a discharge passage 33through which this liquid can be taken off to any desired point. Whenthe pump is stopped some liquid is retained in the reservoir 32, which,therefore maintains the pump full of liquid so that the pump can bereadily started. This res- For seal- 30 ervoir 32 is also adapted toreceive the gas or vapor which is withdrawn from the base portions ofthe impeller chambers during priming, as will curved wall 35 some littledistance radially out- Wardly of the ends' of the impeller blades, as

- shown in Fig. 1. This provides a pocket 36 having an annular lengthsufilcient to coact with several of the blades of-the rotor, in which apressure is created by the ends of the blades as these blades pass fromthe outlet port to a point opposite the end 31 of the pocket 36. Theblades thus build, up a considerable pressure in this pocket in excessof the pressure existing in the'liquid at the outlet port 20 so that bythe time the blades reach a position where the buckets or chambersbetween adjacent blades is about to pass through the close-fittingpassage 39 which seals the inlet from the outlet, there is sunicientpressure created on the liquid to overcome the centrifugal force eiTect,and vapor or gas in the base portions of the impeller, chambers isforced out through a suitable passage or passages which are provided incommunication with the base portions of the buckets of the impeller.These passages communicate with the outside air, or with'the reservoir32 where it is desired that gas or vapor will not be lost. It has beenfound that sufiicient pressure can be created in the pocket 36 toovercome the centrifugal force efiect because the radial extent of theblades is comparatively small,

and also because the blade arrangement is so eiiicient that the speed ofoperation of the pump is moderate, although the pump is quite efficientand capable of operating against very large pressure differentials. 'Theair withdrawal passages, while being large enough for the rapid passageof vapor, may be so restricted in size as to offer considerableresistance to the flow of liquid so that after priming is completed theefliciency of the pumping action is not appreciably impaired.

The air withdrawal passages may extend inwardly into the impeller or maybe provided in the casing. As shown in Fig. 1 there are two passages 40which are arranged in the casing in communication with the sides of theimpeller chambers at opposite sides of the impeller and adjacent thehigh pressure end of the pocket 36, these passages extending to theseparating chamber or reservoir 32 and beyond the pump discharge. Aswill now be apparent, even if there is only sufilcient liquidin the pumpto fill the raceway itself 'at a time when the pump is started, aneffective suction will be created in the suction line extending to theinlet passage l8, by reason of .the driving action created by the bladeson the liquid in the raceway, aid while this driving'action moving ortending to move the liquid to the discharge port may not be sufficientto force the liquid up through the passage at first, there is asufficient pressure created'in the pocket 36 so that air or vapor whichis trapped at the base portions of the impeller pockets or chambers willbe driven off, a small portion at a time, as each pocket or chambercomes into communication with the vapor removing passages 40.,Evidently, therefore, as this gas is taken ofi, the spaces betweenadjacent blades of the impeller will be filled with liquid and theliquid will be drawn up to the pump and discharged from the pump in acontinuousstream. The priming action takes place in an exceedingly shorttime,'so rapidly in fact as to be almost instantaneous under favorableconditions.

casing and impeller of the construction illustrated in Figs. 1 to4'inc1us'ive. The casing is provided with passages 40a communicatingwith the base portions of'the pockets between adjacent blades, just asillustrated in Fig. 1 of the drawings, but these passages 40a extend upto a lead-off passage 48 instead of passing up into the reservoir anddischarge chamber above the pump.

The passage .48 may beopen so that the gas is discharged to theatmosphere, or this passage -may be connected through a suitable conduitinto any suitable receptacle where gas or vapors I are separated fromany liquid that may pass through and liquid returned to the pump suctionwhile the vapor goes to atmosphere. Only a small quantity of liquid can.be .forced out through the passages 40a after the priming of the pump iscompleted because these passages .are quite restricted in size.

While the forms of apparatus herein described constitute preferredembodiments of the invention, it is to be understood that the inventionis not limited to these precise forms of apparatus, and that changes maybe made therein without departing from the scope of the invention whichis defined in the appended claims.

' What is claimed is:"

1. A self-priming rotary pump of the char 'acter described comprising arotatable impeller having a series of outwardly extending peripheralblades which are inclined forwardly in the direction of rotation and ofa radial length less than 10% of the diameter of the impeller, saidblades providing impeller chambers open at a side thereof and of anannular length less than 10% of the diameter of the impeller, animpeller casing providing an inlet passage, a peripheral outlet port andan annular raceway from the inlet to the outlet, said casing having aportion formed to provide a pocket around the impeller periphery justpast the outlet port in the direction of rotation in which a pressureconsiderably greater than the pressure of the liquid at the outlet portis created by the movement of the blades, said pocket being open to theoutlet port and having an annular length several times the annularlength of an impeller chamber, the casing being formed to closelysurround the periphery and sides of the impeller chambers for a distanceat least as great as the annular length of such chambers from the highpressure end of said pocket to the inlet passage of the casing, audit 7gas conducting passage communicating, with the. inner portions of theimpeller chambers when they reach the high pressure end or the pocketfor withdrawing gas successively from the inner portions of the impellerchambers.

2. A self-priming rotary pump' ofgtheichap acter described comprising arotata bleimpeller having a series of outwardly eXtendiiigJperipheraIblades which are inclined forwardly in the dithereof and of an annularlength less than 10% formed to provide a pocket around the impellerperiphery just past the outlet port in the direction of rotation inwhich a pressure considerably greater than the pressure of the liquid atthe outlet port is created by the movement of the blades, said pocketbeing open to the outlet end of said raceway and having an annularlength several times the annular length of an impeller chamber, and agas conducting passage provided in said casing and extending from apoint communicating with a side of the inner portions of the impellerchambers when they reach the high pressure end of the pocket forwithdrawing gas successively from the inner portions of the impellerchambers.

3. A self-priming rotary pump of the character described comprising arotatable impeller having an annular series of impeller blades which areinclined forwardly in the direction of rotation and of a radial lengthless than 10% of the diameter of the impeller, said blades providingimpeller chambers open at a side thereof and of an annular length lessthan 10% of the diameter of the impeller, an impeller casing providingan inlet passage, an outlet port, a discharge passage extending fromsaid outlet port, and an annular raceway from the inlet to the outlet,said casing having a portion formed to provide a pocket around theimpeller periphery Just past the outlet port in the direction ofrotation in which a pressure considerably greater than the pressure ofthe liquid at the outlet port is created by the movement of the blades,said pocket being open to the outlet end of said raceway and having anannular length several times the annular length of an impeller chamber,the casing being formed to closely surround the periphery and sides ofthe impeller chambers for a distance at least as great as the annularlength of such chambers from the high pressure end of said pocket to theinlet passage of the casing, and a gas conducting passage leading to thedischarge passage beyond said outlet port and extending from a pointcommunicating with the inner portions of the impeller chambers when theyreach the high pressure end of the pocket for withdrawing gassuccessively from the inner portions of the impeller chambers.

4. A self-priming rotary pump of the character described comprising arotatable impeller having a series of outwardly extending peripheralblades which are of a radial length less than 10% of the diameter of theimpeller, said blades providing impeller chambers open at a side thereofand of an annular length less than 10% of the diameter of the impeller,an impeller casing providing a tangential inlet passage, a peripheraloutlet port and an annular raceway from the inlet to the outlet, saidcasing having a portion formed to provide a pocket around the impellerperiphery Just past the outlet port in the direction of rotation inwhich a pressure considerably greater than the pressure of the liquid atthe outlet port is created by the movement oi the blades, said pocketbeing open to the outlet end of said raceway and having an annularlength several times the annular length of an impeller chamber, and agas conducting passage provided in. said casing and extending from apoint communicating with aside of the inner portions of ,the impellerchambers when they reach the high pressure end of the pocket forwithdrawing gas successively from the inner portions of the impellerchambers.

5. A self-priming rotary pump of the character described comprising arotatable impeller having a series of outwardly extending peripheralblades which are inclined forwardly in the direction of rotation at anangle of the order of 25 to a radial line from the axis of rotation andof a radial length less than 10% of the diameter of the impeller, saidblades providing impeller chambers open at a side thereof and of anannular length less than 10% of the diameter of the impeller, animpeller casing providing a tangential inlet passage, a peripheraloutlet port and an annular raceway from the inlet to the outlet, saidcasing having a portion formed to provide a pocket around the impellerperiphery just past the outlet port in the direction of rotation inwhich a pressure considerably greater than the pressure of the liquid atthe outlet port is created by the movement of the blades, said pocketbeing open to the outlet end of said raceway and having an annularlength several times the annular length of an impeller chamber, and agas conducting passage provided in said casing and extending. from apoint communicating with a side of the inner portions of the impellerchambers when they reach the high pressure end of the pocket forwithdrawing gas successively from the inner portions of the impellerchambers.

6. A self-priming rotary pump of the character described comprising arotatable impeller having a series of outwardly extending peripheralblades which are inclined forwardly in the direction of rotation at asubstantial angle with the opposite sides of the blades incliningforwardly and outwardly from the blade center, said blades having aradial length less than 10% of the diameter of the impeller andproviding impeller chambers open at opposite sidesthereof andof anannular length less than 10% of the diameter of the impeller, animpeller casing providing an inlet passage, a peripheral outlet port andan annular raceway from the inlet to the outlet, said casing having aportion formed to provide a pocket around the impeller periphery and 01'substantial radial depth throughout its length and located just past theoutlet port in the direction of rotation in which a pressureconsiderably greater than the pressure of the liquid at the outlet portis created by the movement of the blades, said pocket being open to theoutlet end of said raceway and having an annular length several timesthe annular length of an impeller chamber, and a gas conducting passageprovided in said casing and extending from a point communicating with aside of the inner portions'of the impeller chambers when they reach thehigh pressure end 01' the pocket for withdrawing gas successively fromthe inner portions of the impeller chambers.

' FRANCIS E. BRADY.

